We propose to carry-out an epidemiologic study of type II diabetes mellitus and cardiovascular risk factors in a low-income barrio of Mexico City and to compare the results to those which we have previously obtained in San Antonio. Specifically, we will: 1. identify a random sample of blocks in a typical low-income barrio in Mexico City, such that approximately 2250 study-eligible subjects (35-64 year old men and nonpregnant women) reside on the selected blocks; 2. recruit study-eligible individuals into the study; and 3. administer interviews and perform physical and laboratory examinations on all study-eligible individuals. The interviews will include: demographic data; information on socioeconomic status and level of acculturation; medical history; health habits including diet, physical exercise, and smoking. The physical examination will include measurements of blood pressure, obesity, body fat distribution, and skin color, the latter to estimate percent native American genetic admixture. The laboratory examination will include measurements of lipids and lipoproteins, an oral glucose tolerance test to determine the prevalence of diabetes according to the National Diabetes Data Group criteria, fasting and post-glucose load insulin concentrations, and genetic markers. We believe that, compared to San Antonio, the constellation of genetic and environmental factors (especially diet and physical activity) that we will encounter in Mexico City will enable us differentiate further the relative impact of these two determinants on the development of type II diabetes.